bluewave

Very impressive merger of the bands across Suffolk right now.

Approaching 6” on parts of Long Island under these heavy bands.

Heaviest snow of the day right now across much of Long Island.

Heavy snow and 32° in SW Suffolk as the heavy band is right across the area now.

Our first 6”+ event within a week of a 12”+ event for parts of area since March 2018.

33° with snow becoming moderate in SW Suffolk. You can see the band that has been over NJ pushing NE toward Long Island.

Yeah, it gets back to areas of banding often setting up NW of where the raw model QPF output suggests. That’s why this is always discussed in NWS AFDs.

A very special thanks to Walt and others for creating this fantastic product. http://moe.met.fsu.edu/banding/ Bob Hart, FSU David Novak, WPC Walt Drag, NWS PHI Rich Grumm, NWS CTP Last Updated: Sun Feb 7 15:20:02 UTC 2021

The 12z Nam run from yesterday that I posted had the multiple bands.

Snowfall becoming moderate now with giant flakes in SW Suffolk. Temp dropped from 38° to 34°. Snow sticking on all surfaces including paved now.

Temp dropped from 38° to 35° here in SW Suffolk with steady light snow. Giant flakes and an estimated visibility of .75 mile. Also beginning to stick on the cars.

Yeah, I am changing over to light snow now with the temperature down to 37°.

38° and rain here in SW Suffolk before the evap cooling kicks in.

Yeah, these SAL intrusions have become stronger in recent years.

This is a really interesting pattern. It looks like the strongest MJO phase 7 with such intense Greenland blocking. So our area is in the battle zone between the SE Ridge and pressing TPV. The end result will be an unusually high number of winter storm events here.

The MOS did very well with the high temperatures today. The raw 2m Ts really struggle on days like this. Too bad we don’t have ECMWF MOS freely available. KEWR GFS MOS GUIDANCE 2/06/2021 0000 UTC DT /FEB 6 /FEB 7 /FEB 8 / HR 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 18 00 X/N 45 27 36 22 30 TMP 36 34 32 38 42 42 38 33 30 29 29 31 33 33 31 30 28 25 23 27 26 DPT 23 21 20 20 18 16 15 16 17 18 20 25 26 23 20 17 13 10 7 3 7 CLD FW FW FW CL FW FW FW SC BK OV OV OV OV OV BK FW FW CL CL FW SC WDR 27 24 22 25 26 26 26 26 03 03 04 03 02 34 29 31 31 31 31 31 20 WSP 08 03 06 14 15 13 06 03 02 05 07 09 09 07 09 16 13 11 08 07 03

We need a stronger SE Ridge for more winter storm threats to avoid TPV suppression. Notice how the 120 hr forecast on the EPS has corrected to less cold suppression than 240 hrs. That’s why the EPS has so many winter storm threats here now. New run Old run

Yeah, a more extreme version this year of all you mentioned. https://www.washingtonpost.com/weather/2020/12/18/japan-snow-stranded-motorists/ The episode was caused by “ocean-effect snow,” similar in dynamics to lake-effect precipitation that frequents the shores of the Great Lakes. A frigid air mass blowing from the northwest over much warmer waters, in this case between 55 and 60 degrees (12.8 to 15.6 Celsius), allowed heat and moisture from the Sea of Japan to be transported inland in the form of heavy snow. Japan’s high terrain helped focus moisture, too, concentrating it on the upslope, or windward side, of the mountains. That meant snow could fall for days at a time unimpeded, the wintry blast maintained so long as the wind fetch remained from the northwest. Japan’s climate routinely favors hefty snowfall in the mountains. Arctic wintertime cold fronts from Siberia surge south across northeast China and the Korean Peninsula, arriving in Japan after passing over the adjacent sea. The Sea of Japan is kept mild by the Kuroshio Current, akin to the Gulf Stream; a branch of it, called the Tsushima Current, meanders west of the Japanese island chain.

This is what happens when we get one of the strongest west based blocks for this time of year.

Looks like highs maxed out in the upper 40s. So the under 50° day streak continues. This is the 4th longest run since 2010. Number of Consecutive Days Max Temperature < 50 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date Last value also occurred in one or more previous years. Period of record: 2010-01-01 to 2021-02-04 1 63 2015-03-08 2 42 2011-02-13 3 26 2010-02-20 4 22 2021-02-05 5 19 2014-02-21 - 19 2014-02-01 - 19 2010-12-31 6 18 2018-01-10 7 17 2019-03-10 - 17 2019-01-23

Some of the greatest AO and NAO swings occurred in the decade following the publication of this paper. https://www.sciencedaily.com/releases/2009/01/090113101200.htm Swings In North Atlantic Oscillation Variability Linked To Climate Warming January 14, 2009 Woods Hole Oceanographic Institution Using a 218-year-long temperature record from a Bermuda brain coral, researchers have created the first marine-based reconstruction showing the long-term behavior of one of the most important drivers of climate fluctuations in the North Atlantic. Using a 218-year-long temperature record from a Bermuda brain coral, researchers at the Woods Hole Oceanographic Institution (WHOI) have created the first marine-based reconstruction showing the long-term behavior of one of the most important drivers of climate fluctuations in the North Atlantic. The North Atlantic Oscillation (NAO) is a wide-ranging pressure seesaw that drives winter climate over much of North America, Europe and North Africa. Past reconstructions of the NAO have relied mainly on terrestrial, or land-based records, such as tree ring chronologies combined with ice cores and historical climate data. Those records do not fully capture oceanic processes linked to NAO variability, and short instrumental records from relatively few locations limit the understanding of ocean–atmosphere dynamics with regard to NAO behavior. “By analyzing the coral, we were able to look at changes in the ocean relative to changes on land,” said Nathalie Goodkin, lead author of the study published in the December issue of the journal Nature Geoscience. “Because they are slow growing and have long life-spans, corals can provide high resolution records that are well dated and centuries long.” As they grow, corals accrete seasonal and annual growth layers, similar to tree rings. The proportions of trace elements versus the major element (calcium) found in the layers of the skeleton largely depend on the temperature of the seawater in which it was formed. By analyzing the strontium to calcium ratio in the Bermuda brain coral, Goodkin and colleagues — WHOI scientists Konrad Hughen, Scott Doney and William Curry — were able to reconstruct monthly changes in ocean temperatures and evaluate variability of the NAO during both cold and warm periods from the Little Ice Age (1800–1850) to modern day. The research team found the variability of the NAO decade-to-decade (multi-decadal scale) has been larger, swinging more wildly, during the late twentieth century than in the early 1800s, suggesting that variability is linked to the mean temperature of the Northern Hemisphere. This confirms variability previously reported in past terrestrial reconstructions. “When the Industrial Revolution begins and atmospheric temperature becomes warmer, the NAO takes on a much stronger pattern in longer-term behavior,” said Goodkin. “That was suspected before in the instrumental records, but this is the first time it has been documented in records from both the ocean and the atmosphere.” The North Atlantic Oscillation is described by the NAO index, calculated as a weighted difference between the polar low and the subtropical high during the winter season. (For more information about the NAO index, see animation.) In a positive phase, both the low-pressure zone over Iceland and high pressure over the Azores are intensified, resulting in changes in the strength, incidence, and pathway of winter storms crossing the Atlantic. In a negative phase, a weak subtropical high and a weak Icelandic low results in fewer and weaker winter storms crossing on a more west-east pathway. The NAO index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting more than a decade. An unusually long period of positive phase between 1970-2000 led to the suggestion that global warming was affecting the behavior of the NAO. “Anthropogenic (human-related) warming does not appear to be altering whether the NAO is in a positive or negative phase at multi-decadal time scales,” said WHOI paleoclimatologist Konrad Hughen. “It does seem to be increasing variability. Clearly, this has implications for the future.” “As temperatures get warmer, there’s potential for more violent swings of the NAO — the phases becoming even more positive and even more negative,” Hughen added. “If the NAO locks more into these patterns, intense storms will become more intense and droughts will become more severe.” The climatic influence of the NAO extends from the eastern United States to Western Europe, impacting human activities such as shipping, oil drilling, fisheries, hydroelectric power generation and coastal management. Improving the ability to predict shifts in the phase and intensity of the NAO is a prerequisite to mitigating the economic impacts of future climate change. While additional modeling and palaeoclimatic studies are needed, a broad distribution of marine records could advance our knowledge of NAO variability and serve to improve future projections, said Goodkin, now an assistant professor in the Department of Earth Sciences at the University of Hong Kong. A WHOI Ocean and Climate Change Institute Fellowship, and grants from the National Science Foundation and Woods Hole Oceanographic Institution supported this work.

We are on track for only the 4th winter since 1950 with a -1 or lower AO for Dec, Jan, and Feb. The previous years were 09-10, 76-77, and 69-70. But it’s unprecedented for this to occur following a winter with such a strong +AO and polar vortex like we had last year. So the atmosphere continues to exhibit impressive extremes in this new climate era. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table 2020 2.419 3.417 2.641 0.928 -0.027 -0.122 -0.412 -0.381 0.631 -0.072 2.086 -1.736 2021 -2.484 2009 0.800 -0.672 0.121 0.973 1.194 -1.351 -1.356 -0.054 0.875 -1.540 0.459 -3.413 2010 -2.587 -4.266 -0.432 -0.275 -0.919 -0.013 0.435 -0.117 -0.865 -0.467 -0.376 -2.631 1976 0.034 1.656 0.587 0.440 0.060 0.328 -0.325 0.559 -0.743 -0.804 -0.087 -2.074 1977 -3.767 -2.010 0.344 1.329 0.104 -0.226 -0.492 -1.412 0.586 -0.009 0.605 -0.240 1969 -2.967 -3.114 -1.582 0.438 -0.720 -0.348 0.410 -0.782 -0.083 0.098 0.326 -1.856 1970 -2.412 -1.325 -2.084 0.302 0.531 0.875 0.139 -0.263 0.030 0.098 0.378 -0.399